Update new tests

Author: varkor

src/test/ui/issues/issue-48132.rs

@@ -27,5 +27,5 @@ where I: Iterator,
 }
 
 fn main() {
-    outer(std::iter::once(&1).cloned());
+    let _ = outer(std::iter::once(&1).cloned());
 }

src/test/ui/type-alias-impl-trait/issue-58951.rs

@@ -7,7 +7,7 @@ type A = impl Iterator;
 fn def_a() -> A { 0..1 }
 
 pub fn use_a() {
-    def_a().map(|x| x);
+    let _ = def_a().map(|x| x);
 }
 
 fn main() {}